Simulation Of Land Use Change In Nanchang Based On Ecosystem Services

In recent years,with the rapid development of industrialization and urbanization,environmental pressure has increased and the ecological protection crisis has become increasingly serious.Therefore,it is of great significance to scientifically evaluate the current ecosystem service capacity of the city,and to simulate the future land use layout with the goal of improving the quality of the ecological environment and realizing the coordinated development of economy and ecology.Based on this,this paper takes Nanchang City as the research area.Firstly,InVEST model is used to evaluate the three ecosystem services of water yield,carbon storage and habitat quality in Nanchang City from 2000 to 2020,and the importance of ecosystem services is evaluated by comprehensive zoning method.Secondly,based on the results of the importance zoning of ecosystem services,the PLUS model was used to simulate the land use layout of Nanchang City in 2030 to make it conform to the set multiple development scenarios.Finally,the ecosystem services under different scenarios in 2030 are compared and analyzed,and the optimal development scenario is selected.The clustering and outlier analysis method is used to identify the key control areas of ecological protection under the optimal development scenario,and the future land use and protection strategies of Nanchang City are proposed.The main findings are as follows:(1)There are significant differences in the levels of various ecosystem services in Nanchang from 2000-2020.The total water yield of Nanchang City from 2000 to 2020 is6.209 billion m~3,10.564 billion m~3and 7.661 billion m~3respectively.Different land use types show different water production capacity.The carbon storage in 2000-2020 is 9.41×10~7t,9.32×10~7t and 8.66×10~7t,respectively,showing a decreasing trend,and the carbon storage function is decreasing.The average habitat quality indexes from 2000 to 2020 were0.5621,0.5616 and 0.5577,respectively,showing a decreasing trend year by year.The areas with significant changes were concentrated in the central urban area of Nanchang City and the eastern part of Jinxian County.The area of each important area of integrated ecosystem services in Nanchang City from 2000 to 2020 is:very important area>general important area>relatively important area>extremely important area>highly important area.The area of highly important,extremely important and very important areas is increasing,and the area of relatively important areas is decreasing.Although the general importance fluctuates,it generally shows a decreasing trend.(2)Based on the PLUS model,the land use layout under the natural development scenario,ecological security scenario,ecological agriculture scenario and ecological development scenario in Nanchang City in 2030 is simulated.The results show that the area reduction of cultivated land is the largest in the ecological security scenario and the smallest in the ecological agriculture scenario.The area of forest land increased in all four scenarios,with the largest increase in the ecological security scenario.The area of grassland and unused land changed the least in different scenarios,grassland decreased slightly,and unused land increased slightly.The increase of water area in natural development scenario,ecological security scenario and ecological development scenario is similar and larger,and the area decreases in ecological agriculture scenario.The expansion area of construction land is the largest in the natural development scenario and the ecological development scenario,followed by the ecological security scenario,and the slowest expansion is the ecological agriculture scenario.(3)In the comprehensive ecosystem service zoning of Nanchang City in 2030,the proportion distribution of each important zoning under different development scenarios is roughly the same.In all scenarios,the very important level is the main,and the proportion of highly important areas is the smallest.Compared with the area of comprehensive ecosystem service importance zoning in 2020,it is found that the area of general important,relatively important and very important areas has been converted to a higher level of importance zoning to varying degrees.Among them,the area of extremely important and highly important areas has increased the most under the ecological security scenario,and the comprehensive proportion is the highest.The ecological security scenario is determined as the optimal development scenario in 2030.(4)Based on the identification of key areas,a land use control strategy for Nanchang City is proposed.The results of the clustering and outlier analysis of ecosystem services under the 2030 ecological security scenario for Nanchang City show that the HL gathering area is mainly located in the northwestern part of Nanchang County,the northern part of East Lake District and the western part of Nanchang City,while the LH gathering area is mainly located in the southeastern waters of the study area.Based on the results of importance zoning,clustering and outlier analysis of ecosystem services under the ecological security scenario,the areas with high degree of concentration and more than 30km~2in extremely important areas,highly important areas,HL gathering areas and LH gathering areas are extracted as key control areas for ecological protection for classification and control,so as to improve the fine management level of future land use and protection.